Silverlight AppDomainAssertAssertion Failed in XNA WP7 game with Farseer engine

I've been working on my first wp7 game. This 2d game is Labyrinth with a ball controlled by accelerometer. When I reach the end of level (green spot)
I ever get Silverlight AppDomainAssertAssertion Failed in Debug Console
all errors
If you want I can upload my whole project.